A new lack-of-fit test for quantile regression models, that is suitable even with highdimensional
covariates, is proposed. The test is based on the cumulative sum of residuals
with respect to unidimensional linear projections of the covariates. To approximate the
critical values of the test, a wild bootstrap mechanism convenient for quantile regression
is used. An extensive simulation study was undertaken that shows the good performance of
the new test, particularly when the dimension of the covariate is high. The test can also be
applied and performs well under heteroscedastic regression models. The test is illustrated
with real data about the economic growth of 161 countries